The Hebrew word for virgin (‘almah) literally means “young woman,” also having the connotation of a virgin.
Immanuel, a name for Jesus Christ, comes from words in Hebrew that mean “God with us.” Immanuel is a name-title given as a sign of God’s deliverance (see Isaiah 7:14). Isaiah’s reference to Immanuel had both a possible historic meaning and a prophetic meaning. In its most immediate meaning, it could indicate a child to be born in Isaiah’s time whose coming of age operated as a sign (see 2 Nephi 17:16–19). In its more important prophetic meaning, Immanuel is specifically identified by Matthew as a prophecy of Jesus’s birth into mortality (see Matthew 1:18–25). The name also appears in latter-day scripture (see 2 Nephi 17:14; 18:8; D&C 128:22). (For more information, see Guide to the Scriptures, “Immanuel,” 117; Bible Dictionary, “Immanuel,” 706.)
“God with us” was meant to reassure King Ahaz that if he turned to the Lord, then God would help him. Elder Jeffrey R. Holland of the Quorum of the Twelve Apostles explained how this also became another type and shadow of the Savior: “There are plural or parallel elements to this prophecy, as with so much of Isaiah’s writing. The most immediate meaning was probably focused on Isaiah’s wife, a pure and good woman who brought forth a son about this time, the child becoming a type and shadow of the greater, later fulfillment of the prophecy that would be realized in the birth of Jesus Christ. The symbolism in the dual prophecy acquires additional importance when we realize that Isaiah’s wife may have been of royal blood, and therefore her son would have been royalty of the line of David. Here again is a type, a prefiguration of the greater Immanuel, Jesus Christ, the ultimate son of David, the royal King who would be born of a literal virgin. Indeed, his title Immanuel would be carried forward to the latter days, being applied to the Savior in section 128 verse 22 of the Doctrine and Covenants” (Christ and the New Covenant [1997], 79).